Wikipedia is celebrating ten years today.
This is an example of the amazing democratization of information the internet and Web 2.0 have wrought. Other examples include things such as blogs, social networking sites, and “sharing” services like YouTube. Web 2.0 gives easy access to pretty much whatever information you want (no guarantees of quality, though). Web 2.0 also gives you easy access to other people. In many ways, we all know more facts and more people.
In light of my comments above, Wikipedia is an excellent example of Web 2.0. It is certainly more accurate than some random rant page, if only because so many people see it. This also has disadvantages, as it is obvious that a lot more people are interested in celebrities than in third world legislators. Hence, the surplus of coverage in one area and the deficiency in the other. Other problems might be the bureaucracy and power structure behind the users.
All in all, Wikipedia is far from perfect; one of the reasons it got so big was because it got started first. There are certain to be challenges in the years ahead, as society and the internet continue to evolve.